1. Filed of this Invention
The present invention relates to a method of manufacturing a composite material wing and a composite material wing and, more particularly, a method of manufacturing a composite material wing for fastening a lower skin portion structure and an upper skin portion structure via mechanical fastening device and a composite material wing that can be manufactured by this manufacturing method. The description of Japanese Patent Application No. 2001-165850 filed on Sep. 3, 2001 including the specification, drawings and abstract is incorporated by reference in its entirely.
2. Description of Related Art
In recent years, in many cases a wing box structure of the main wing of the aircraft is manufactured by employing not only the metallic material but also composite material made of the lightweight/high strength fiber reinforced plastic (referred simply to as the xe2x80x9ccomposite materialxe2x80x9d hereinafter) For example, there is the method of manufacturing the wing box structure of the main wing by fabricating separately upper/lower skins, front/rear spars, the stiffening members such as the stringers, etc., which constitute the wing box structure, and the coupling members such as the shear tie, etc. by the composite material, and then fastening or adhering such members by virtue of the mechanical fastening device such as bolts, nuts, pins, rivets, etc. (referred to as the xe2x80x9cfastenersxe2x80x9d hereinafter) or the adhesive.
Also, there is the method of manufacturing the wing box structure of the main wing by integrally fabricating the front portion of the wing box structure, which is constructed by the front spar, the skin, and the stiffening members (referred to as the xe2x80x9cfront spar structurexe2x80x9d hereinafter), and the rear portion of the wing box structure, which is constructed by the rear spar, the skin, and the stiffening members (referred to as the xe2x80x9crear spar structurexe2x80x9d hereinafter), respectively by virtue of the resin-impregnating curing method such as the RTM (Resin Transfer Molding) method or the RFI (Resin Film Infusion) method, and then fastening these parts by means of the fasteners.
However, according to the method of manufacturing the wing box structure of the main wing by fabricating separately respective parts such as the skins, the front and rear spars, the stiffening members, the coupling members, etc. by the composite material and then fastening these parts by means of the fasteners, the curing/molding process often becomes different for different parts. For this reason, it takes much time to fabricate/prepare a variety of parts by the limited equipment so that the production cycle is prolonged.
Also, according to the method of fabricating separately the above parts by the composite material and then fastening these parts by means of the fasteners, the clearances are often generated in the fastened portions between respective parts (e.g., the fastened portion between the spar and the skin, the fastened portion between the skin and the stiffening members, etc.). Since the wing box structure of the main wing is also used as the fuel tank, the sealing process must be applied to fill such clearances, or shapes of neighboring portions of the fastened portions between respective parts must be repaired. Therefore, it takes much time and labor to execute the fine adjustment or the alignment prior to the fastening operation and as a result the cost of production is increased.
While, according to the method of manufacturing the wing box structure of the main wing by fabricating separately the parts by the composite material respectively and then adhering these parts by means of the adhesive, like the above fastening method by using the fasteners, it takes much time to fabricate/prepare a variety of parts by the limited equipments and thus the production cycle is prolonged. Also, according to the method of adhering respective parts by means of the adhesive, the clearances are also generated in the adhered portion between respective parts. Since such clearances must be filled with the adhesive, it takes much time and labor as a result the cost of production is increased.
Also, according to the method of manufacturing the wing box structure of the main wing by fabricating integrally the front spar structure and the rear spar structure by employing the resin-impregnating curing method respectively and then fastening these structures by means of the fasteners, the front spar structure and the rear spar structure have large and complicated cavities therein and therefore special split core jigs are needed to mold such cavities. Thus, the cost of fabricating the special core jigs is increased. Also, the mold-releasing process must be applied to the special split core jigs prior to the manufacture of the front spar structure and the rear spar structure, and also the special split core jigs must be separated and cleaned after the manufacture. As a result, the cost of production is increased.
It is a subject of the present invention to provide a method of manufacturing a composite material wing capable of reducing the labor and the assembling man-hour required for the manufacture to thus shorten the production cycle and reduce the production cost considerably, and a composite material wing that can be manufactured by this manufacturing method.
In order to achieve the above subject, as shown in FIG. 1 to FIG. 5, for example, the invention set forth in a first aspect of the present invention provides A method of manufacturing a composite material wing comprising: a lower skin portion structure manufacturing step of manufacturing a lower skin portion structure that contains a lower skin, a front spar, a rear spar, a lower stringer and a lower rib chord for stiffening the lower skin; an upper skin portion structure manufacturing step of manufacturing an upper skin portion structure that contains an upper skin, an upper stringer and an upper rib chord for stiffening the upper skin; and an upper and lower skin portion structure fastening step of fastening the lower skin portion structure and the upper skin portion structure; wherein the lower skin portion structure manufacturing step includes, a front spar molding step of molding a front spar, which has at least one front rib post that projects toward a wing rear side at predetermined position, in a state that a thermosetting resin is primarily cured, a rear spar molding step of molding a rear spar, which has at least one rear rib post that projects toward a wing front side at position opposing to the predetermined position, in the state that the thermosetting resin is primarily cured, a lower stringer molding step of molding the lower stringer for stiffening the lower skin in the state that the thermosetting resin is primarily cured, a lower rib chord prepreg laminating step of laminating a lower rib chord prepreg that are provided vertically along an inner shape of the lower skin in a chord direction at wing positions at which the rib post is positioned, a lower skin prepreg laminating step of laminating an lower skin prepreg on a lower molding jig that has an under surface shape of the wing, an arranging step of arranging the front spar, the rear spar, the lower stringer, and the lower rib chord prepreg on the lower skin prepreg via an adhesive respectively, a covering step of covering the lower skin prepreg, the front spar, the rear spar, the lower stringer, and the lower rib chord prepreg with a covering device, and a curing and molding step of exhausting, pressurizing, and heating portions that are covered with the covering device, the upper skin portion structure manufacturing step includes, an upper stringer molding step of molding the upper stringer for stiffening the upper skin in the state that the thermosetting resin is primarily cured, an upper rib chord prepreg laminating step of laminating upper rib chord prepreg that is provided vertically along an inner shape of the upper skin in the chord direction at wing position at which the rib post is positioned, an upper skin prepreg laminating step of laminating an upper skin prepreg on an upper skin jig having an upper surface shape of the wing, an arranging step of arranging the upper stringer and the upper rib chord prepreg on the upper skin prepreg via the adhesive, a covering step of covering the upper skin prepreg, the upper stringer, and the upper rib chord prepreg with the covering device, and a curing and molding step of exhausting, pressurizing, and heating portions that are covered with the covering device, and the upper and lower skin portion structures fastening step includes, a rib fabricating step of fabricating ribs each having a predetermined shape by a composite material or a metal, a first rib fastening step of fastening the ribs to the front rib post and the rear rib post and the lower rib chords of the lower skin portion structure by mechanical fastening device, an upper and lower fastening step of fastening spar of the lower skin portion structure, to which the ribs are coupled, to the skin of the upper skin portion structure by the mechanical fastening device, and a second rib fastening step of fastening the ribs to the upper rib chords of the upper skin portion structure by mechanical fastening device.
According to the invention as set forth in the first aspect of the present invention, there are provided the step of manufacturing the front/rear spars, the lower stringers, the lower skin prepreg, and the lower rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method and also the step of manufacturing the upper skin portion structure by using the upper stringers, the upper skin prepreg, and the upper rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method. Therefore, the time and labor that are required for manufacturing/preparing separately the parts such as the under/upper skins, the front/rear spars, the rib chords, etc., which have the different curing process, can be reduced. As a result, the production cycle of the composite material wind can be reduced considerably.
Also, according to the invention set forth in the first aspect, there are provided the step of manufacturing the front/rear spars, the lower stringers, the lower skin prepreg, and the lower rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method and also the step of manufacturing the upper skin portion structure by using the upper stringers, the upper skin prepreg, and the upper rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method. Therefore, because of the flexibility of the prepregs, the clearance is never generated in the fastened portions between respective manufactured parts, for example, the fastened portions of the front/rear spars and the skins, the fastened portions between the stringers and the skin.
Accordingly, the operation of fastening respective parts by the fasteners, the sealing process of burying the clearances in the fastened portions of respective parts, the operation of repairing the shapes of respective parts near the fastened portions, the operation of adhering respective parts by the adhesive, and the operation of burying the clearances in the fastened portions between the parts by the adhesive can be eliminated. Therefore, the time and labor required for these operations can be reduced. As a result, the cost of production of the composite material wing can be reduced considerably.
In addition, according to the invention set forth in The first aspect of the present invention, there are provided the step of manufacturing the front/rear spars, the lower stringers, the lower skin prepreg, and the lower rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method and also the step of manufacturing the upper skin portion structure by using the upper stringers, the upper skin prepreg, and the upper rib chord prepregs, which are primarily cured, by virtue of the so-called co-bonding method. Therefore, there is no necessity to employ the special split core jigs when the lower skin portion structure and the upper skin portion structure are manufactured. Accordingly, the cost of fabricating the special split core jigs can be reduced. Also, the mold-releasing process of the special core jigs and the splitting/cleaning operations of the special core jigs can be omitted. As a result, the cost of production of the composite material wing can be reduced extremely.
Further, according to the first aspect, there are provided the step of manufacturing the front/rear spars having the rib posts and the lower skin portion structure and the upper skin portion structure having the rib chords and also the step of fastening the lower skin portion structure and the upper skin portion structure by using the rib posts and the rib chords as the fastening portions to the ribs. Therefore, the step of manufacturing the composite material wing can be simplified considerably.
In the invention set forth in a second aspect of the present invention, a method of manufacturing a composite material wing according to the first aspect, wherein the front spar and the rear spar that molded in the primarily-cured state are manufactured by an RTM method and an RFI method.
According to the second aspect of the present invention, not only the advantages of the invention set forth in the first aspect can also be achieved, but also the high quality front/rear spars can be effectively manufactured since the RTM method or the RFI method is employed without the employment of the prepreg when the front spar and the rear spar are to be molded in the primarily cured state. As a result, the high quality composite material wing can be effectively manufactured.
As shown in FIG. 1, for example, the invention set forth in a third aspect of the present invention provides a composite material wing comprising: a front spar and a rear spar; a lower skin that is jointed integrally to the front spar and the rear spar by an adhering device; an upper skin that is fastened to the front spar and the rear spar by mechanical fastening device; a plurality of stringers that are jointed integrally to inner surfaces of the lower skin and the upper skin by the adhering device to extend in a wing span direction; and ribs that are fastened to members that are integrally jointed to the front spar, the rear spar, the lower skin, and the upper skin respectively by mechanical fastening device.
In the composite material wing according to the invention set forth in the third aspect of the present invention, the stringers are jointed integrally to the lower skin and the upper skin by the adhering device, and also the front spar and the rear spar and the lower skin are integrally molded by the adhering device. Therefore, the strength can be assured sufficiently, and also the sealing process of filling the clearances in the fastened portions between respective parts, the operation of repairing the shapes of respective parts near the fastened portions, the operation of adhering respective parts by the adhesive, and the operation of filling the clearances in the fastened portions between the parts by the adhesive can be eliminated. As a result, the time and labor required for these operations can be reduced, and also the cost of production can be reduced considerably.